Degradation of Di- Through Hepta-Chlorobiphenyls in Clophen Oil Using Microorganisms Isolated from Long Term PCBs Contaminated Soil

Abstract

Present work describes microbial degradation of selected polychlorinated biphenyls (PCBs) congeners in Clophen oil which is used as transformer oil and contains high concentration of PCBs. Indigenous PCBs degrading bacteria were isolated from Clophen oil contaminated soil using enrichment culture technique. A 15 days study was carried out to assess the biodegradation potential of two bacterial cultures and their consortium for Clophen oil with a final PCBs concentration of 100 mg kg(-1). The degradation capability of the individual bacterium and the consortium towards the varying range of PCBs congeners (di- through hepta-chlorobiphenyls) was determined using GCMS. Also, dehydrogenase enzyme was estimated to assess the microbial activity. Maximum degradation was observed in treatment containing consortium that resulted in up to 97 % degradation of PCB-44 which is a tetra chlorinated biphenyl whereas, hexa chlorinated biphenyl congener (PCB-153) was degraded up to 90 % by the consortium. This indicates that the degradation capability of microbial consortium was significantly higher than that of individual cultures. Furthermore, the results suggest that for degradation of lower as well as higher chlorinated PCB congeners; a microbial consortium is required rather than individual cultures.

Metagenomic Analysis of a Biphenyl-Degrading Soil Bacterial Consortium Reveals the Metabolic Roles of Specific Populations

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Advances and perspective in bioremediation of polychlorinated biphenyl-contaminated soils

“…It is reported that between 1920 and early 1980s approximately 1.5 million tons of PCBs were manufactured throughout the globe and as a result of which a significant amount of PCBs has been released in the environment (Piper 2005; Sharma et al 2014). Due to their extensive use in past and lack of appropriate disposal technologies, PCBs and their congeners have attained ubiquitous distribution from the Arctic to the Antarctic.…”

Phytoremediation: General Account and Its Application

“…Several methods are developed to manage or remediate these pollutants which include physical, chemical, and biological methods. Biological methods have an advantage over physical and chemical methods being cost incurred and environment friendly but have limitations with respect to effi ciency Sharma et al 2014 ). Soil microfl ora is able to degrade most of the organic contaminants, whereas metals need immobilization or physical removal.…”